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Derivative Financial Instruments - Narrative (Details) | 9 Months Ended |
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Sep. 30, 2024 USD ($) counterparty | Dec. 31, 2023 USD ($)
Derivative [Line Items] |  |
Number of central counterparties | counterparty | 2 |
Notional value | $ 943,285,000 | $ 1,906,092,000
Derivative, fair value, amount offset against collateral, net | 6,000,000 | 9,000,000
Estimated accumulated gain (loss) to be reclassified in next 12 months | (20,000,000) |
Cash collateral held relative to derivative exposure | 0 | 0
Cash collateral pledged | 6,000,000 | $ 9,000,000
CME |  |
Derivative [Line Items] |  |
Notional value | $ 855,000,000 |
Percent of total notional derivative contracts | 90.60% |
Amount of variation margin included as settlement | $ (20,000,000) |
LCH |  |
Derivative [Line Items] |  |
Notional value | $ 88,000,000 |
Percent of total notional derivative contracts | 9.40% |
Amount of variation margin included as settlement | $ (1,000,000) |

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- Definition The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480870/815-30-50-1 + Details
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- Definition Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 5 -SubTopic 10 -Topic 815 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480463/815-10-45-5 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -SubTopic 20 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483466/210-20-50-3 + Details
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- Definition The net amount as of the balance sheet date of the fair value of derivative assets and derivative liabilities that in accordance with the entity's accounting policy were offset against collateral under a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-8 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480237/815-40-50-5 + Details
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